Agrobacterium-mediated gene transfer—efficiency across plant groups With respect to natural transformation by Agrobacterium tumefaciens (Ti plasmid systems), which statement best reflects its inherent efficiency across major plant groups in classical practice?

Introduction / Context:Agrobacterium naturally infects many dicotyledonous species, transferring T-DNA into the plant genome. Historically and inherently, this system was most efficient with dicots. Monocot transformation required later innovations (e.g., super-binary vectors, tissue wounding, specific genotypes), and biolistics was often used for cereals.

Given Data / Assumptions:

• Classical textbooks emphasize dicot susceptibility in natural infections.
• The question asks about inherent efficiency, not modern engineered workarounds.
• Binary vectors and improved protocols have expanded host range post-hoc.

Concept / Approach:Differentiate between the natural proclivity of Agrobacterium and the broad applicability achieved through advanced methods. The inherently efficient group is dicots.

Step-by-Step Solution:

Verification / Alternative check:Legacy transformation pipelines for tobacco, tomato, and petunia relied on Agrobacterium; cereal crops often required alternative methods until later protocol refinements.

Why Other Options Are Wrong:

• (b) Contradicts the natural host range.
• (c) Overgeneralizes current capabilities as inherent.
• (d) Reverses the historical pattern.

Common Pitfalls:Conflating today’s engineered versatility with the organism’s native propensity.

Final Answer:Only with dicots